The oil pressure sensor in a 2005 Chevy TrailBlazer is found simply over the oil channel at the front of the motor. A few indications of a terrible or bombing sensor is the oil pressure light is on,the oil pressure measure peruses at nothing and the motor is running fine and not mIS Firing. In the first place,begin by checking the motor oil level,assuming that motor oil level is full,logical the issue is the sensor. To eliminate the sensor You really want either an oil pressure switch attachment or a 1-1/16" profound well attachment with SRX focuses and a wrench. Jack the front of the vehicle up and put jack remains under it. Separate the electrical connector and put the attachment over the sensor and pivot it counterclockwise.